As mentioned in Frank's article linked above, you're looking at a significant expense if you have to build private utilities.

Of course, I could also get private/hard money, but that sort of freaks me out - what if the property doesn’t hit the target ARV and I can’t pay off the lender / 70% isn’t enough?

Check with your state, but we only have to give 20 day notice for MTM leases.

I have had a property for 3 years, handled by a property management, in Oakland, CA and is under rent control.And we just noticed that one of our tenants (who was placed by the old owner) has a 2 bedroom voucher but was placed in a 3 bedroom unit. 

If you go that route you need several documents to protect you and effectuate taking over mortgage payments (POA, notice to release, etc. )If you only have a strict 90 days to do this then in your agreement that should be spelled out but several things depend on your relative and how secure he wants to be in the fact that you will basically hand the house back over to him at the end of 90 days if you haven't sold it.

My only theory is he wants our mortgage to look clean until he has the chance to sell it to a big bank (it's a small private lender), and he's only looking out for the company's interests. 

I notice myself losing motivation lately and on a recent BP podcast Brandon Turner said something to the effect of 'just get something done' (speaking to newbies about that first deal).  

I dont know the price yet, but I want to get private money set up before then.

Private Lenders, Hard Money lenders, or doing a "cash rich" Partner that will make you be able to do your entire project. 

I've also noticed lots of new investors on BP that are looking to purchase their first investment property without knowing the first thing about managing one.